Brush-like Grindstone

ABSTRACT

A brush-like grindstone ( 1 ) has threadlike grinding elements ( 2 ) each being a thread that is a collection of long inorganic fibers and is impregnated with resin and solidified. To grind work (W), the grindstone ( 1 ) is moved relative to the work (W) with the forward ends of the threadlike grinding elements ( 2 ) pressed against the work (W). In order to prevent the grinding elements ( 2 ) from breaking, each threadlike grinding element ( 2 ) is curved from its base end to its forward end with high hardness of the grinding elements ( 2 ) maintained. Also, the grinding elements ( 2 ) are formed in an elliptic or oblong cross-sectional shape whose minor axis is aligned with the direction of the curve. Therefore, the grinding elements ( 2 ) have extremely high rigidity in the direction perpendicular to the direction of the curve but they easily deform in the direction of the curve. Consequently, the grinding elements ( 2 ) softly engages the work (W) at their forward ends and, when excessive force acts on the elements ( 2 ), the brush-like grindstone ( 1 ) does not break because the elements ( 2 ) deform to absorb the force.

TECHNICAL FIELD

The present invention relates to a brush-like grindstone that is usedfor burr removal and grinding processes.

BACKGROUND ART

Precision parts that are used for automobile and aircraft components aremanufactured with high precision and accuracy by automated equipmentsuch as NC benches, NC cutters, machining centers, robots andspecialized processing equipment that employ tools such as end mills,drills, dies and taps. In addition, the frames and other parts ofelectronics equipment are produced from die-cast parts formed frommagnesium and aluminum. Grinding processes are carried out on theseworkpieces using gritted nylon brushes, brass brushes, wire brushes, andthe like in order to remove processing marks, tool marks, burrs and thelike. However, gritted nylon brushes, brass brushes, and wire brusheshave low grit content and low hardness, and thus have inferior grindingcapacity due to their inferior stiffness, and there have thus beenproblems with inefficient grinding.

Thus, the applicant of the present invention provides a brush-likegrindstone in which a holder holds a plurality of filamentous bodiesformed by impregnating bundled fibers formed from alumina fiber, siliconcarbide fiber, carbon fiber, silicon nitride fiber, or glass fiber withbinder resin, which is then caused to harden. This type of brush-likegrindstone that employs long inorganic fibers has high hardness andstiffness, which provides high grinding capacity and long life (seePatent Document 1, for example).

-   Patent Document 1: JP A 2000-94344

DISCLOSURE OF INVENTION Technical Problem

However, even with the brush-like grindstone disclosed in PatentDocument 1, when irregularities are present on the surface, it is notpossible to grind or remove burrs in the corners of the depressionssimply by moving the brush-like grindstone along the surface of thework. In addition, there is the problem that the long inorganic fibersused in the brush-like grindstone break in many locations due to theirhigh hardness when the brush-like grindstone is moved while impinging onthe workpiece with high force.

In view of the above problems, an object of the present invention is toprovide a brush-like grindstone whereby it is possible to preventbreakage of the linear grinding materials while also maintaining highhardness in the linear grinding materials that are produced byimpregnating bundles of long inorganic fibers with a resin, which isthen caused to harden.

Solution to Problem

In order to resolve the above problems, according to the presentinvention, there is provided a brush-like grindstone wherein a pluralityof linear grinding materials are held in a holder, the linear grindingmaterials being obtained by impregnating an assemblage of long inorganicfiber filaments with a resin, which is caused to harden; wherein theplurality of linear grinding materials are curved in at least onelocation from the proximal end to the distal end.

According to the present invention, each of the plurality of lineargrinding materials is preferably curved over the entire length thereoffrom the proximal ends to the distal ends.

According to the brush-like grindstone of the present invention, aworkpiece is ground by moving the grindstone relative to the workpiecein a state in which the distal ends of the linear grinding materials arepressed against the work. Because the linear grinding materials areproduced by impregnating long inorganic fiber bundles with a resin,which is then caused to harden, the long inorganic fibers thatsubstantially function as the grinding materials have high density, highhardness, and high rigidity. Consequently, the brush-like grindstone ofthe present invention has high grinding capacity. In addition, accordingto the present invention, the linear grinding materials are in a curvedstate, even when the brush-like grindstone is at rest, and thus readilydeform in the direction of curvature. As a result, with the brush-likegrindstone according to the present invention, the linear grindingmaterials impinge softly on the workpiece with their distal endsrelative to brush-like grindstones in which the linear grindingmaterials extend perpendicularly. In addition, the linear grindingmaterials do not break because they deform to absorb excessive forcewhen excessive force is applied.

In the present invention, a configuration may be utilized in which eachof the plurality of linear grinding materials extends radially from anouter circumferential side surface of the holder, and curvescircumferentially in the same direction.

In the present invention, a configuration may also be utilized in whicheach of the plurality of linear grinding materials extends radially fromthe outer circumferential side surface of the holder, and curves in onedirection in the axial direction of the holder.

In the present invention, a configuration may be utilized in which aplurality of holders are disposed in the axial direction of the holders,and each of the plurality of linear grinding materials is held on eachof the plurality of holders.

In the present invention, a configuration may be utilized in which twoholders are disposed as a pair in the axial direction of the holders,each of the plurality of linear grinding materials extends radially fromthe circumferential surface of the two holders and curves in a directionwhereby the distal ends of the plurality of linear grinding materialsheld in the two holders are close to one another.

In the present invention, a configuration may be utilized in which eachof the plurality of linear grinding materials extends in an axialdirection from the end surface of one side of the holder in the axialdirection, and curves outwards from the inside of the end surface of theone side.

In the present invention, a configuration may be adopted in which eachof the plurality of linear grinding materials extends in the axialdirection from the end surface of one side of the holder in the axialdirection, and curves inwards from the outside of the end surface of theone side.

In the present invention, it is preferable for the plurality of lineargrinding materials to be held in the holder as a plurality of bundles.By adopting such a configuration, the advantage is presented that chipsgenerated in the grinding process are efficiently discharged and heatdissipation efficiency is increased. In addition, a configuration isused in which the plurality of linear grinding materials are fixed inthe holder in small groups; therefore, it is possible to prevent thelinear grinding materials from being pulled out. As a result, theadvantage is presented that the brush-like grindstone of the presentinvention is very safe.

In the present invention, a configuration may be adopted in which theplurality of linear grinding materials are held along the entirety ofthe circumferential direction in a circumferential groove formed on anouter circumferential side surface or on an end surface of one side ofthe holder.

In the present invention, it is preferable to provide the plurality oflinear grinding materials with elliptical or oval cross sections inwhich the minor axis faces the direction of curvature. By utilizing thisconfiguration, the materials deform when excessive force is applied tothe linear grinding materials, and the excessive force is absorbed, thuspreventing breakage.

In the present invention, it is preferable for a rotating drive shaft toextend from the holder in the axial direction. By utilizing this type ofconfiguration, it is possible to drive the brush-like grindstone bysimple linkage of the drive shaft to a drive device.

In the present invention, alumina fibers, silicon carbide fibers, carbonfibers, silicon nitride fibers, glass fibers, and the like may be usedas the long inorganic fibers.

BRIEF DESCRIPTION OF DRAWINGS

FIGS. 1(A), 1(B) and 1(C) are a perspective view, plan view, anddescriptive view of the brush-like grindstone of a first embodiment ofthe present invention, where the perspective view schematically portraysa cross-section of the linear grinding material used in the brush-likegrindstone.

FIGS. 2(A) and 2(B) are a perspective view and side view of thebrush-like grindstone of a second embodiment of the present invention.

FIGS. 3(A) and 3(B) are a perspective view and side view of thebrush-like grindstone of a third embodiment of the present invention.

FIGS. 4(A) and 4(B) are a perspective view and side view of thebrush-like grindstone of a fourth embodiment of the present invention.

FIGS. 5(A) and 5(B) are a perspective view and a side view of thebrush-like grindstone of a fifth embodiment of the present invention.

FIG. 6 is a side view of the brush-like grindstone of a sixth embodimentof the present invention.

FIG. 7 is a descriptive view showing a usage example of the brush-likegrindstone of a sixth embodiment of the present invention.

FIG. 8 is a descriptive view showing the brush-like grindstone of thesixth embodiment of the present invention and a usage example thereof.

FIGS. 9(A) and 9(B) are a plan view and a side view of the brush-likegrindstone of a seventh embodiment of the present invention.

FIG. 10 is a descriptive diagram showing a usage example of thebrush-like grindstone of the seventh embodiment of the presentinvention.

FIGS. 11(A) and 11(B) are a plan view and side view of the brush-likegrindstone of an eighth embodiment of the present invention.

FIG. 12 is a descriptive diagram showing a usage example of thebrush-like grindstone of the eighth embodiment of the present invention.

FIG. 13 is a descriptive diagram showing a case in which the lineargrinding materials are bent at one location from the proximal endtowards the distal end in the brush-like grindstone according to thepresent invention.

FIG. 14 is a descriptive diagram showing another example in which thelinear grinding materials are bent at one location from the proximal endtowards the distal end in the brush-like grindstone according to thepresent invention.

SYMBOLS

-   1 Brush-like grindstone-   2 Linear grinding material-   5 Holder-   20 Grinding material bundle-   51 Holder shaft hole-   53 Embedding hole-   55 Rotational drive shaft-   57 Outer peripheral surface of the holder-   59 End surface on one side of the holder-   W Workpiece

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiments of the present invention are described in reference to thedrawings. In the drawings referenced in the descriptions that follow, areduced number of grinding material bundles or linear grinding materialsare represented in order to facilitate understanding of the structure ofeach member.

Embodiment 1

FIGS. 1(A), 1(B) and 1(C) are a perspective view, plan view, anddescriptive view of the brush-like grindstone of Embodiment 1 of thepresent invention, where the descriptive view schematically portrays across-section of the linear grinding materials used in the brush-likegrindstone. The brush-like grindstone 1 presented in FIGS. 1(A) and (B)has a structure in which a metal holder 5 holds a plurality of lineargrinding materials 2 produced by impregnating long inorganic fiberbundles with a resin, which is then caused to harden. The holder 5 has acylindrical shape in which a shaft hole 51 is formed in the center andpasses through in the axial direction. A rotational drive shaft 55 thatis inserted into this shaft hole 51 is linked to the holder 5 by a screw(not shown) that is tightened from the side.

In this embodiment, the linear grinding materials 2 are produced byimpregnating bundled filaments of long alumina fibers used as the longinorganic fibers with a thermosetting binder resin such as siliconeresin, phenol resin, epoxy resin, polyimide resin, polymaleimide resin,unsaturated polyester resin, or urethane resin, which is caused toharden. Nylon or another thermoplastic resin may also be used as thebinder resin. The bundled filaments may be a bundled material of 250 to3000 strands of long alumina fibers with fiber diameters of 8 to 50 μm,and the diameter of the bundled filament is 0.1 to 2 mm. A material thatis not twisted can be used as the bundled filament.

A plurality of embedding holes 53 are formed at equivalent angularintervals in the outer peripheral side surface 57 of the holder 5 in thebrush-like grindstone 1 of the present invention. A plurality of lineargrinding materials 2 are then fixed at their proximal ends with anadhesive such as silicon resin-based or epoxy resin-based adhesive ineach of the plurality of embedding holes 53 in a state in which they arebundled as round grinding material bundles 20 (groups of linear grindingmaterials 2). For this reason, the plurality of linear grindingmaterials 2 extend radially from the outer peripheral side surface 57 ofthe holder 5 in the form of grinding material bundles 20. The pluralityof linear grinding materials 2 are each in an isolated state when formedas the grinding material bundles 20.

All of the linear grinding materials 2 are curved along their entirelengths from their proximal ends to their distal ends towards one sidein the circumferential direction, for example, the clockwise directionCW. All of the grinding material bundles 20 are also curved in theclockwise direction CW in accordance therewith. In addition, as shown inFIG. 1(C), the linear grinding materials 2 have an elliptical or ovalcross-section with the minor axis faces the direction of curvature.

When the brush-like grindstone 1 of this embodiment is used in order togrind or remove burrs from the surface of a workpiece W, as shown inFIGS. 1(A) and 1(B), rotation is carried out in the direction oppositethe direction of curvature of the linear grinding material 2(counterclockwise direction CCW) about the axis L with the drive shaft55 linked to the drive device of the grinder, and the distal ends of thelinear grinding materials 2 are brought into contact with the surface ofthe workpiece W that is situated at the outer periphery of thebrush-like grindstone 1. As a result, the long inorganic fibers that areexposed at the tips of the linear grinding materials 2 in the brush-likegrindstone 1 cut away and grind off the irregularities and burrs of theworkpiece W, acting substantially as grinding materials. When thisgrinding operation is carried out, in addition to rotational movement,there are also cases in which movement occurs along the surface of theworkpiece W in the form of reciprocating movement, oscillation,vibration, or combinations of these movements. In addition, combinationsof movements may also be carried out in which the brush-like grindstone1 is moved towards and away from the workpiece W.

In producing this type of brush-like grindstone 1, when the curvedlinear grinding materials 2 are formed, first, 1000 individual longalumina fibers with diameters of, for example, 10 to 15 μm are firstbundled together in a flat, untwisted state, and a bobbin of the bundledfilament (strand) that has been continuously wound is placed in a creel.Next, the bundled filament is taken from the bobbin and dipped in binderresin such as epoxy resin, thereby being impregnated with binder resin,whereupon the excess binder resin is removed with a squeeze roll. Asthis occurs, the material is wound upon itself around the circumferenceof a cylindrical or cylinder-shaped winding roll. In accordance withtension applied to the bundled filament, the location of each of thelong alumina fibers that constitutes a bundled filament is shifted, andthe bundled filament is deformed to produce a state in which it has anelliptical or oval cross-section. When the binder resin is subsequentlycaused to harden, a linear grinding material 2 is formed which is curvedalong the circumference of the winding roll. The cross-section thelinear grinding materials 2 is elliptical or oval, with the minor axisfacing the direction of curvature of the linear grinding material 2.Next, the linear grinding material 2 that has been wound on thecircumference of the winding roll is cut in the axial direction of thewinding roll, thereby separating the linear grinding materials 2 fromthe winding roll. The linear grinding materials 2 are then cut andaligned at the desired length. Next, the prescribed number of lineargrinding materials 2 are bundled with the directions of curvaturematching, and the ends are inserted into the embedding holes 53 of theholder 5 and secured in the holder 5 using an adhesive such as an epoxyresin-based or silicone resin-based adhesive.

According to this production method, curved linear grinding materials 2can be efficiently formed, and by changing the external diameterdimension of the winding roll, the linear grinding materials 2 can beformed while being curved at a prescribed radius of curvature. Inaddition, because the external form of the wound roll can be made ovularor elliptical, curved linear grinding materials 2 can be formed withlinear regions or radii of curvature that vary depending on thelocation.

As described above, with the brush-like grindstone 1 of this embodiment,the grindstone is moved relative to the workpiece W in a state in whichthe tips of the linear grinding material 2 are in contact with theworkpiece W, whereby the workpiece W is ground. Because the lineargrinding materials 2 are produced, in this case, by impregnating longinorganic fiber bundles with resin, which is then caused to harden, thelong inorganic fibers that substantially function as the grindingmaterials have high density, high hardness, and high rigidity.Consequently, the brush-like grindstone 1 of this embodiment has highgrinding capacity.

In addition, with the brush-like grindstone 1 of this embodiment, all ofthe plurality of linear grinding materials 2 are in a state in whichthey curve from their proximal ends to their distal ends, while alsohaving elliptical or oval cross-sections in which the minor axis facesthe direction of curvature. For this reason, the linear grindingmaterials 2 can readily deform in the direction of curvature, whilehaving extremely high rigidity in the direction that is perpendicular tothe direction of curvature. Consequently, with the brush-like grindstone1 of this embodiment, the linear grinding materials 2 softly impinge onthe workpiece W at their distal ends in comparison to brush-likegrindstones in which the linear grinding materials 2 extend straight andperpendicularly. In addition, the linear grinding materials 2 do notbreak because they deform to absorb the excessive force when excessiveforce has been supplied.

In addition, because the linear grinding materials 2 are fixed in theholder 5 in a state in which they are in small groups as grindingmaterial bundles 20, the advantage is presented that chips during thegrinding process are efficiently discharged, and heat dissipationeffects are enhanced. For this reason, the brush-like grindstone 1 ofthis embodiment has superior grinding properties. Consequently, thematerial can be used with high precision and good efficiency in carryingout deburring and grinding processes on precision processed parts. Inaddition, the linear grinding material 2 allows the cost of thebrush-like grindstone 1 to be decreased because a small number can beused with high grinding performance. Moreover, because a configurationis utilized in which a large number of linear grinding materials 2 arefixed to the holder 5 in small groups, the linear grinding materials 2can be kept from being pulled out. For this reason, the advantage ispresented that the brush-like grindstone 1 of this embodiment has highsafety.

Modification of Embodiment 1

Embodiment 1 described above has a configuration in which the pluralityof linear grinding materials 2 are held in a holder 5 as a plurality ofgrinding material bundles 20, but a configuration may also be utilizedin which a circumferential groove is formed in a outer peripheral sidesurface 57 of the holder 5, and the plurality of linear grindingmaterials 2 are held across the entire circumferential length of thiscircumferential groove.

Embodiment 2

FIGS. 2(A) and (B) are a perspective view and a side view of thebrush-like grindstone of embodiment 2 of the present invention. Withthis embodiment and embodiments 3 to 8 below, the basic configuration isthe same as in embodiment 1, and the descriptions thus employ the samesymbols for parts having the same function. The brush-like grindstone 1shown in FIGS. 2(A) and 2(B) also has a configuration that is similar tothat of embodiment 1, in which bundles of long alumina fibers (longinorganic fibers) are impregnated with a resin, which is caused toharden to produce linear grinding materials 2, a plurality of which areheld by a metal holder 5. The holder 5 is a hollow cylinder in which ashaft hole 51 that passes through it in the axial direction L is formedat the center, with a rotational drive shaft 55 linked therewith.

In the brush-like grindstone of this embodiment, a plurality ofembedding holes 53 are formed with equivalent angular spacing on theouter circumferential surface 57 of the holder 5. The plurality oflinear grinding materials 2 are then fixed at their proximal ends usingadhesive such as silicon resin-based or epoxy resin-based adhesive inthe plurality of embedding holes 53 in a state in which round bundlesare produced as grinding material bundles 20 (groups of linear grindingmaterials 2). Consequently, the plurality of linear grinding materials 2extend radially from the circumferential surface 57 of the holder 5 asgrinding material bundles 20. The plurality of linear grinding materials2 are separated from each other in the form of grinding material bundles20.

All of the linear grinding materials 2 curve to one side in thedirection of the axis line L from their bases to their tips, andaccordingly all of the grinding material bundles 20 curve to one side inthe direction of the axis line L. In addition, the linear grindingmaterials 2 are provided with elliptical or oval cross sections in whichthe minor axis faces the direction of curvature, as has been describedin reference to FIG. 1(C).

When the brush-like grindstone 1 of this embodiment is used in order togrind or remove burrs from the surface of a workpiece W, rotation isperformed, for example, in the counterclockwise direction CCW as shownin FIGS. 2(A) and 2(B) with the drive shaft 55 linked to the drivedevice of the grinder, and the tips of the linear grinding materials 2are brought into contact with the surface of the workpiece W that isdisposed at the outer periphery of the brush-like grindstone 1. As aresult, the long inorganic fibers that are exposed at the tips of thelinear grinding materials 2 of the brush-like grindstone 1 grind thematerial by cutting away the irregularities and burrs in the workpieceW.

With the brush-like grindstone 1 having this configuration, the lineargrinding materials 2 are produced in the same manner as in Embodiment 1by impregnating long inorganic fiber bundles with resin, which is thencaused to harden, thus producing high hardness and high grindingcapacity. In addition, all of the plurality of linear grinding materials2 curve from their bases to their tips, and have elliptical or ovalcross sections in which the minor axis faces in the direction ofcurvature. For this reason, the linear grinding materials 2 readilydeform in the direction of curvature. As a result, the linear grindingmaterials 2 softly impinge upon the workpiece W at their distal ends anddeform to absorb excessive force when excessive force is supplied inmaking them impinge upon the irregularities or the like of the surfaceof the workpiece W, so that breakage does not occur. In addition,because the linear grinding materials 2 are fixed in the holder 5 in astate in which they are in small groups as grinding material bundles 20,the advantage is presented that chips generated in the grinding processare efficiently discharged, and heat dissipation effects are enhanced.

Modification of Embodiment 2

Embodiment 2 described above has a configuration in which the pluralityof linear grinding materials 2 are held in a holder 5 as a plurality ofgrinding material bundles 20, but a configuration may also be employedin which a circumferential groove is formed in the outer peripheral sidesurface 57 of the holder 5, and a plurality of linear grinding materials2 are held across the entire circumferential length of thiscircumferential groove.

Embodiment 3

FIGS. 3(A) and 3(B) are perspective and side views of the brush-likegrindstone of Embodiment 3 of the present invention. The brush-likegrindstone 1 in FIGS. 3(A) and 3(B), as with Embodiments 1 and 2, has aconfiguration in which fiber bundles of long aluminum fibers (longinorganic fibers) are impregnated with a resin, which is then caused toharden to produce linear grinding materials 2, a plurality of which areheld in a metal holder 5. The holder 5 is a cylinder with a shaft hole51 that passes through in the direction of the axis line L at itscenter. A rotational drive shaft 55 is linked therewith.

With the brush-like grindstone 1 of this embodiment, a plurality ofembedding holes 53 are formed with equivalent angular spacing on theouter peripheral side surface 57 of the holder 5. The plurality oflinear grinding materials 2 are fixed in the plurality of embeddingholes 53 using an adhesive such as a silicone resin-based or epoxyresin-based adhesive at their proximal ends in a state in which thegrinding materials are bundled as round grinding material bundles 20(assemblages of linear grinding materials 2). Consequently, theplurality of linear grinding materials 2 extend radially from the outerperipheral side surface 57 of the holder 5 as grinding material bundles20. Each of the plurality of linear grinding materials 2 is in anisolated state as grinding material bundles 20.

All of the linear grinding materials 2 curve to one side in thedirection of the axis line L from their bases to their tips, andaccordingly all of the grinding material bundles 20 curve to one side inthe direction of the axis line L. In addition, the linear grindingmaterials 2 are provided with elliptical or oval cross sections in whichthe minor axis faces the direction of curvature, as has been describedin reference to FIG. 1(C).

With the brush-like grindstone 1 of this embodiment, the linear grindingmaterial 2 is longer than in the brush-like grindstone 1 of Embodiment2, and the distal ends of the linear grinding materials 2 extendapproximately parallel to the axis line L. Consequently, when thebrush-like grindstone 1 of this embodiment is used in order to grind orremove burrs from the surface of a workpiece W, rotation is made tooccur, for example, in the counterclockwise direction CCW about the axisline L as shown in FIGS. 3(A) and 3(B) with the drive shaft 55 linked tothe drive device of the grinder. The workpiece W is thus ground by thedistal ends of the linear grinding materials 2 with the surface (surfaceto be ground) facing the axis line L.

With the brush-like grindstone 1 having this configuration, as withEmbodiment 1, the linear grinding materials 2 are produced byimpregnating long inorganic fiber bundles with a resin, which is thencaused to harden, and thus have high hardness and high grindingcapacity. In addition, all of the plurality of linear grinding materials2 are in a state in which they are curved from their proximal ends totheir distal ends, and have an elliptical or oval cross section in whichthe minor axis faces the direction of curvature. For this reason, thelinear grinding materials 2 readily deform in the direction ofcurvature. Consequently, the linear grinding materials 2 softly impingeupon the workpiece W at their distal ends and deform to absorb excessiveforce when excessive force is supplied in making them impinge upon theirregularities or the like in the surface of the workpiece W, so thatbreakage does not occur. In addition, because the linear grindingmaterials 2 are secures in the holder 5 in a state in which they are insmall groups as grinding material bundles 20, the advantage is presentedthat chips generated in the grinding process are efficiently discharged,and heat dissipation effects are enhanced.

Modification of Embodiment 3

Embodiment 3 described above has a configuration in which the pluralityof linear grinding materials 2 are held in a holder 5 as a plurality ofgrinding material bundles 20, but a configuration may also be employedin which a circumferential groove is formed in the outer peripheral sidesurface 57 of the holder 5, and a plurality of linear grinding materials2 are held across the entire circumferential length of thiscircumferential groove.

Embodiment 4

FIGS. 4(A) and 4(B) are a perspective view and plan view of a brush-likegrindstone of Embodiment 4 of the present invention. The brush-likegrindstone 1 shown in FIGS. 4(A) and 4(B), as in Embodiment 1, has aconfiguration in which bundles of long alumina fibers (long inorganicfibers) are impregnated with a resin, which is caused to harden toproduce linear grinding materials 2, a plurality of which are held in ametal holder 5. The holder 5 is cylindrical with a shaft hole 51 that isformed at its center and passes through in the direction of the axisline L. A rotational drive shaft 55 that inserts into the shaft hole 51is linked to the holder 5 with a screw that is tightened from the side(not shown).

A plurality of holders 5, e.g., three holders, are disposed along theaxis line L. In addition, a plurality of embedding holes 53 are formedat equivalent angular spacing on the outer peripheral side surface 57 ofthe three holders 5. The plurality of linear grinding materials 2 arefixed in the plurality of embedding holes 53 using an adhesive such as asilicone resin-based or epoxy resin-based adhesive at their proximalends in a state in which the linear grinding materials are bundled asround grinding material bundles 20 (assemblages of linear grindingmaterials 2). Consequently, the plurality of linear grinding materials 2extend radially from the outer peripheral side surface 57 of the holder5 as grinding material bundles 20. In this embodiment, the holdingpositions of the linear grinding materials 2 are shiftedcircumferentially between adjacent holders 5. Each of the plurality oflinear grinding materials 2 is in an isolated state as grinding materialbundles 20.

With all of the three holders 5, the linear grinding materials 2 curveto one side in the circumferential direction, e.g., in the clockwise CWdirection, from their proximal ends to their distal ends, andaccordingly all of the grinding material bundles 20 curve in theclockwise direction CW. In addition, the linear grinding materials 2, asdescribed in reference to FIG. 1(C), have an elliptical or oval crosssection in which the minor axis faces the direction of curvature.

When the brush-like grindstone 1 of this embodiment is used in order togrind or remove burrs from the surface of a workpiece W, in the samemanner as in Embodiment 1, the brush-like grindstone 1 is rotated in thecounter-clockwise direction CCW as shown in FIGS. 4(A) and 4(B) with thedrive shaft 55 linked to the drive device of the grinder, and thesurface of the workpiece W is disposed at the outer periphery of thebrush-like grindstone 1 and is ground by the distal ends of the lineargrinding materials 2.

Although a configuration is used in this embodiment in which threeholders 5 are stacked in three levels, a plurality of sets of embeddingholes 53 formed at equivalent angular spacing in the circumferentialdirection may be formed with shifted positions along the axis line L ina single holder 5. In addition, the number of holders 5 may be 2 or 4 orgreater.

Modification of Embodiment 4

Embodiment 4 described above has a configuration in which the pluralityof linear grinding materials 2 are held in a plurality of holders 5 as aplurality of grinding material bundles 20, but a configuration may alsobe employed in which a circumferential groove is formed in the outerperipheral side surface 57 of each of the plurality of holders 5, and aplurality of linear grinding materials 2 are held across the entirecircumferential length of this circumferential groove.

Embodiment 5

FIGS. 5(A) and 5(B) are a perspective view and side view of a brush-likegrindstone of Embodiment of the present invention. The brush-likegrindstone 1 shown in FIGS. 5(A and 5(B), as in Embodiment 1, has aconfiguration in which assemblages of long alumina fibers (longinorganic fibers) are impregnated with a resin, which is caused toharden to produce linear grinding materials 2, a plurality of which areheld in a metal holder 5. The holder 5 is cylindrical with a shaft hole51 that is formed at its center and passes through in the direction ofthe axis line L. A rotational drive shaft 55 that inserts into the shafthole 51 is linked to the holder 5 with a screw that is tightened fromthe side (not shown).

Three holders 5 are disposed along the axis line L. A plurality ofembedding holes 53 are formed at equivalent angular spacing on the outerperipheral side surface 57 of each of the three holders 5. The pluralityof linear grinding materials 2 are cured in the plurality of embeddingholes 53 using an adhesive such as a silicone resin-based or epoxyresin-based adhesive at their proximal ends in a state in which thegrinding materials are bundled as round grinding material bundles 20(assemblages of linear grinding materials 2). Consequently, theplurality of linear grinding materials 2 extend radially from the outerperipheral side surface 57 of the holder 5 as grinding material bundles20. In this embodiment, of the three holders 5, the holding positions ofthe linear grinding materials 2 are shifted circumferentially betweenadjacent holders 5. Each of the plurality of linear grinding materials 2are in an isolated state as grinding material bundles 20.

With all of the three holders 5, the linear grinding materials 2 curveto one side in the direction of the axis line L from their proximal endsto their distal ends, and accordingly all of the grinding materialbundles 20 curve to one side in the direction of the axis line L. Inaddition, the linear grinding materials 2, as described in reference toFIG. 1(C), have elliptical or oval cross sections in which the minoraxis faces the direction of curvature.

When the brush-like grindstone 1 of this embodiment is used in order togrind or remove burrs from the surface of a workpiece W, in the samemanner as in the second embodiment, the brush-like grindstone 1 isrotated in the counterclockwise direction CCW as shown in FIGS. 5(A) and5(B) with the drive shaft 55 linked to the drive device of the grinder,and the surface of the workpiece W is disposed at the outer periphery ofthe brush-like grindstone 1 and is ground by the distal ends of thelinear grinding materials 2.

Although a configuration is used in this embodiment in which threeholders 5 are stacked in three levels, a plurality of sets of embeddingholes 53 formed at equivalent angular spacing in the circumferentialdirection may be formed with shifted positions along the axis line L ina single holder 5. In addition, the number of holders 5 may be 2 or 4 orgreater.

Modification of Embodiment 5

Embodiment 5 described above has a configuration in which the pluralityof linear grinding materials 2 are held in a plurality of holders 5 as aplurality of grinding material bundles 20, but a configuration may alsobe employed in which a circumferential groove is formed in the outerperipheral side surface 57 of each of the plurality of holders 5, and aplurality of linear grinding materials 2 are held across the entirecircumferential length of this circumferential groove.

Embodiment 6

FIG. 6 is a side view of a brush-like grindstone of Embodiment 6 of thepresent invention. FIG. 7 is a descriptive diagram showing a usageexample of the brush-like grindstone of this embodiment. The brush-likegrindstone 1 shown in FIG. 6, as with Embodiment 1, has a configurationin which bundles of long alumina fibers (long inorganic fibers) areimpregnated with a resin, which is caused to harden to produce lineargrinding materials 2, a plurality of which are held in a metal holder 5.The holder 5 is cylindrical with a shaft hole 51 that is formed at itscenter and passes through in the direction of the axis line L. Arotational drive shaft 55 that inserts into the shaft hole 51 is linkedto the holder 5 with a screw (not shown) that is tightened from theside.

Two holders 5 are disposed along the axis line L. In addition, aplurality of embedding holes 53 are formed at equivalent angular spacingon the circumferential side surfaces 57 of the two holders 5. Theplurality of linear grinding materials 2 are fixed in the plurality ofembedding holes 53 using an adhesive such as a silicone resin-based orepoxy resin-based adhesive at their proximal ends in a state in whichthe plurality of linear grinding materials 2 are bundled as roundgrinding material bundles 20 (assemblages of linear grinding materials2). Consequently, the plurality of linear grinding materials 2 extendradially from the outer peripheral side surface 57 of the holder 5 asgrinding material bundles 20. In this embodiment, the holding positionsof the linear grinding materials 2 are shifted circumferentially betweenadjacent holders 5. Each of the plurality of linear grinding materials 2is in an isolated state as grinding material bundles 20.

With one of the pair of two holders 5, the linear grinding materials 2curve to one side in the direction of the axis line L from theirproximal ends to their distal ends, and accordingly all of the grindingmaterial bundles 20 curve in the direction of the axis line L. With theother of the pair of two holders 5, on the other hand, the lineargrinding materials curve towards the other side in the direction of theaxis line L from their proximal ends to the their distal ends, andaccordingly all of the grinding material bundles 20 curve towards theother side in the direction of the axis line L. Consequently, theplurality of linear grinding materials 2 held in the two holders 5 curvein directions whereby each of their distal ends approaches the other. Inaddition, as shown in FIG. 1(C), the linear grinding materials 2 have anelliptical or oval cross section in which the minor axis faces thedirection of curvature.

When the brush-like grindstone 1 of this embodiment is used in order togrind or remove burrs from the surface of a workpiece W, the brush-likegrindstone 1 is rotated about the axis line L as shown in FIG. (6) withthe drive shaft 55 linked to the drive device of the grinder, and thesurface of the workpiece W is disposed at the outer periphery of thebrush-like grindstone 1 and is ground by the distal ends of the lineargrinding materials 2.

In addition, as shown in FIG. 7, when a male thread W12 is formed on ashaft body W11 and the brush-like grindstone 1 of this embodiment isused in order to finish the male threads W12, the thread peaks andvalleys can be efficiently finished.

The two holders 5 are fixed to the rotational drive shaft 55 with screwsin this embodiment; therefore, when the linear grinding materials 2 areabraded and shortened, the two holders 5 can be moved closer in order toadjust the positional relationship of the distal ends of the lineargrinding materials 2.

Although a configuration is used in this embodiment in which two holders5 are disposed at two levels and the positional relationship can beadjusted, two sets of embedding holes 53 formed at equivalent angularspacing in the circumferential direction may be formed with shiftedpositions along the axis line L in a single holder 5. The plurality oflinear grinding materials 2 may also be held in the respective sets ofembedding holes 53 in an orientation whereby the distal ends curve in adirection whereby they are close to one another.

Modification 11of Embodiment 6

Although a configuration is used in Embodiment 6 in which a plurality oflinear grinding materials 2 are held in a plurality of holders 5 as aplurality of grinding material bundles 20, a configuration may beutilized in which a circumferential groove is formed in the outerperipheral side surface 57 in each of the plurality of holders 5, and aplurality of linear grinding materials 2 are held over the entirecircumferential length of this circumferential groove.

Modification 2 of Embodiment 6

Embodiment 6 described above has a configuration in which the distalends of the plurality of linear grinding materials 2 held in the twoholders 5 face each other. As shown in FIG. 8, however, a configurationmay be utilized in which the two holders 5 are closer than in the stateshown in FIG. 6, and the plurality of linear grinding materials 2 heldin the two holders 5 intersect each other. In this case, the inner sidesurfaces of the protrusions W2 that oppose each other at a prescribedspacing in a workpiece W21 can be finished simultaneously

Embodiment 7

FIGS. 9(A) and 9(B) are a plan view and side view of a brush-likegrindstone of Embodiment of the present invention. FIG. 10 is adescriptive diagram showing a usage example of the brush-like grindstoneof this embodiment. The brush-like grindstone 1 shown in FIGS. 9(A) and9(B), as in Embodiment 1, has a configuration in which bundles of longalumina fibers (long inorganic fibers) are impregnated with a resin,which is caused to harden to produce linear grinding materials 2, aplurality of which are held in a metal holder 5. The holder 5 iscylindrical with a shaft hole 51 that is formed at its center and passesthrough in the direction of the axis line L. A rotational drive shaft 55that inserts into the shaft hole 51 is linked to the holder 5 with ascrew that is tightened from the side (not shown).

In the brush-like grindstone 1 of this embodiment, a plurality ofembedding holes 53 are formed at equivalent angular spacing on the endsurface 59 of one side of the holder 5 in the direction of the axis lineL. The plurality of linear grinding materials 2 are fixed in theplurality of embedding holes 53 using an adhesive such as a siliconeresin-based or epoxy resin-based adhesive at their proximal ends in astate in which the grinding materials are bundled as round grindingmaterial bundles 20 (assemblages of linear grinding materials 2). Inthis state, the linear grinding materials 2 extend in the direction ofthe axis line L. Each of the plurality of linear grinding materials 2are in an isolated state as grinding material bundles 20.

All of the linear grinding materials 2 curve outwards from the endsurface 59 of one side of the holder 5 from their proximal ends to theirdistal ends, and accordingly all of the grinding material bundles 20curve outwards. In addition, the linear grinding materials 2, asdescribed in reference to FIG. 1(C), have an elliptical or oval crosssection in which the minor axis faces the direction of curvature.

Consequently, when the brush-like grindstone 1 of this embodiment isused in order to grind or remove burrs from the surface of a workpieceW, rotation is made to occur in the counter-clockwise direction CCW, forexample, as shown in FIGS. 9(A) and 9(B), with the drive shaft 55 linkedto the drive device of the grinder. The workpiece W is ground by thedistal ends of the linear grinding materials 2 with its surface (surfaceto be ground) facing in the direction of the axis line L.

With the brush-like grindstone 1 configured in this manner, because thelinear grinding materials 2 are formed by impregnating long inorganicfiber bundled filaments with a resin that is then caused to harden, highhardness and high grinding capacity are produced in the same manner asin the first embodiment. In addition, all of the plurality of lineargrinding materials 2 curve from their bases to their tips, and haveelliptical or oval cross sections in which the minor axis faces in thedirection of curvature. For this reason, the linear grinding materials 2readily deform in the direction of curvature. As a result, the lineargrinding materials 2 softly impinge upon the workpiece W at their distalends and deform to absorb excessive force when excessive force issupplied in making them impinge upon the irregularities or the like ofthe surface of the workpiece W, so that breakage does not occur. Inaddition, because the linear grinding materials 2 are fixed in theholder 5 in a state in which they are in small groups as grindingmaterial bundles 20, the advantage is presented that chips generated inthe grinding process are efficiently discharged, and heat dissipationeffects are enhanced.

In addition, the brush-like grindstone 1 of this embodiment is suitablefor finishing female threading W32 formed on a workpiece W31 as shown inFIG. 10(A), for finishing the inner circumferential surface of a holeW34 formed in a workpiece as shown in FIG. 10(B), or for deburringintersecting parts of intersecting holes W36 and W37 formed in aworkpiece 5, as shown in FIG. 10(C).

Modification of Embodiment 7

Embodiment described above has a configuration in which the plurality oflinear grinding materials 2 are held in a holder 5 as a plurality ofgrinding material bundles 20, but a configuration may also be employedin which a circumferential groove is formed in the end surface 59 on oneside of the holder 5, and a plurality of linear grinding materials 2 areheld across the entire circumferential length of this circumferentialgroove.

Embodiment 8

FIGS. 11(A) and 11(B) are a plan view and side view of a brush-likegrindstone of Embodiment 8 of the present invention. FIG. 12 is adescriptive diagram showing a usage example of the brush-like grindstoneof this embodiment. The brush-like grindstone 1 shown in FIGS. 11(A) and11(B), as in Embodiment 1, has a configuration in which bundles of longalumina fibers (long inorganic fibers) are impregnated with a resin,which is caused to harden to produce linear grinding materials 2, aplurality of which are held in a metal holder 5. The holder 5 iscylindrical with a shaft hole 51 that is formed at its center and passesthrough in the direction of the axis line L. A rotational drive shaft 55that inserts into the shaft hole 51 is linked to the holder 5 with ascrew (not shown) that is tightened from the side.

In the brush-like grindstone 1 of this embodiment, a plurality ofembedding holes 53 are formed at equivalent angular spacing on the endsurface 59 of one side of the holder 5 in the direction of the axis lineL. The plurality of linear grinding materials 2 are fixed in theplurality of embedding holes 53 using an adhesive such as a siliconeresin-based or epoxy resin-based adhesive at their proximal ends in astate in which the grinding materials are bundled as round grindingmaterial bundles 20 (assemblages of linear grinding materials 2). Inthis state, the linear grinding materials 2 extend in the direction ofthe axis line L. Each of the plurality of linear grinding materials 2are in an isolated state as grinding material bundles 20.

All of the linear grinding materials 2 curve outwards from the endsurface 59 of one side of the holder 5 from their proximal ends to theirdistal ends, and accordingly all of the grinding material bundles 20curve outwards. In addition, the linear grinding materials 2, asdescribed in reference to FIG. 1(C), have an elliptical or oval crosssection in which the minor axis faces the direction of curvature.

When the brush-like grindstone 1 of this embodiment is used in order togrind or remove burrs from the surface of a workpiece W, rotation ismade to occur about the axis L; for example, in the counter-clockwisedirection CCW, as shown in FIGS. 11(A) and 11(B), with the drive shaft55 linked to the drive device of the grinder. The workpiece W is groundby the distal ends of the linear grinding materials 2 with its surface(surface to be ground) facing in the direction of the axis line L.

The brush-like grindstone 1 of this embodiment is suitable for finishingmale threading W42 formed in a workpiece W41 as shown in FIG. 12(A), andfor finishing the outer circumferential surface of a shaft-shapedworkpiece W43.

With the brush-like grindstone 1 configured in this manner, because thelinear grinding materials 2 are formed by impregnating long inorganicfiber bundled filaments with a resin that is then caused to harden, highhardness and high grinding capacity are produced in the same manner asin the first embodiment. In addition, all of the plurality of lineargrinding materials 2 curve from their bases to their tips, and haveelliptical or oval cross sections in which the minor axis faces in thedirection of curvature. For this reason, the linear grinding materials 2readily deform in the direction of curvature. As a result, the lineargrinding materials 2 softly impinge upon the workpiece W at their distalends and deform to absorb excessive force when excessive force issupplied in making them impinge upon the irregularities or the like ofthe surface of the workpiece W, so that breakage does not occur. Inaddition, because the linear grinding materials 2 are fixed in theholder 5 in a state in which they are in small groups as grindingmaterial bundles 20, the advantage is presented that chips generated inthe grinding process are efficiently discharged, and heat dissipationeffects are enhanced.

Modification of Embodiment 8

Embodiment 8 described above has a configuration in which the pluralityof linear grinding materials 2 are held in a holder 5 as a plurality ofgrinding material bundles 20, but a configuration may also be employedin which a circumferential groove is formed in the end surface 59 on oneside of the holder 5, and a plurality of linear grinding materials 2 areheld across the entire circumferential length of this circumferentialgroove.

Another Embodiments

In all of the above embodiments, all of the linear grinding materials 2are configured so that the entire material curves from the proximal endto the distal end. However, as shown in FIGS. 13(A) and 13(13) and inFIG. 14, a configuration may also be utilized in which the lineargrinding materials 2 curve at one location from the proximal end to thedistal end. In producing this type of brush-like grindstone 1, first,1000 long alumina fibers (individual long alumina fibers) are bundledtogether in a flat and untwisted state, and the continuously woundbundled filament (strand) is dipped in a binder resin such as epoxyresin, allowing the bundled filament to be impregnated with the binderresin. Next, for example, the material is wound upon itself on thecircumferential surface of a square roller in which the square partbecomes R. The binder resin is then allowed to harden, and the lineargrinding materials 2 are cut off.

In all of the above embodiments, examples were described in which aplurality of linear grinding materials 2 are held in a metal holder 5,where the grinding materials are produced by impregnating long aluminafiber (long inorganic fiber) bundles with a resin, which was then causedto harden. However, the present invention may also be utilized forproducing a brush-like grindstone 1 in which the long inorganic fibersare silicon carbide fibers, carbon fibers, silicon nitride fibers, orglass fibers.

In all of the above embodiments, a configuration is used in which thelinear grinding materials 2 are fixed in the holder 5 in a state inwhich they are in small groups as grinding material bundles 20, or thelinear grinding materials 2 are fixed in a circumferential groovewithout being in small groups of grinding material bundles 20. However,the present invention may also be utilized in order to produce abrush-like grindstone 1 in which the linear grinding materials 2 areheld in a holder 5 as a single bundle.

In all of the above embodiments, untwisted materials are used for thebundled filaments used in the linear grinding materials 2, but thelinear grinding materials 2 may be configured using twisted bundledfilaments. In addition, some linear grinding materials that do not curvebut extend linearly can be included in the curved linear grindingmaterials 2.

INDUSTRIAL APPLICABILITY

As described above, the linear grinding material of the brush-likegrindstone of the present invention is produced by impregnating longinorganic fiber bundles with a resin, which is then caused to harden. Asa result, the long inorganic fibers that substantially function asgrinding materials have high rigidity, density and hardness, thusproviding high grinding capacity. In addition, the linear grindingmaterials are in a curved state, and thus readily deform in thedirection of curvature. Consequently, with the brush-like grindstone ofthe present invention, the linear grinding material softly impinges uponthe workpiece at its distal ends relative to brush-like grindstones inwhich the linear grinding materials extend linearly. The materials thusdeform and absorb excessive force when excessive force is applied,thereby preventing breakage.

1. A brush-like grindstone wherein a plurality of linear grindingmaterials are held in a holder, the linear grinding materials isobtained by impregnating an assemblage of long inorganic fiber filamentswith a resin and hardening the resin, and an circumferential outer sidesurface of the holder is a circular circumferential surface,characterized in that: the long inorganic fibers are selected fromalumina fibers, silicon carbide fibers, carbon fibers, silicon nitridefibers, and glass fibers, and each of the plurality of linear grindingmaterials is curved in at least one location from its proximal end toits distal end.
 2. The brush-like grindstone according to claim 1,wherein each of the plurality of linear grinding materials is curvedover the entire length thereof from the proximal end to the distal end.3. The brush-like grindstone according to claim 1, wherein each of theplurality of linear grinding materials extends radially from an outercircumferential side surface of the holder, and curves circumferentiallyin the same direction.
 4. The brush-like grindstone according to claim3, wherein: a plurality of the holders are disposed in an axialdirection of the holders, and each of the plurality of linear grindingmaterials is held on each of the plurality of holders.
 5. The brush-likegrindstone according to claim 1, wherein the plurality of lineargrinding materials extend radially from an outer circumferential sidesurface of the holder, and curve toward one side in an axial directionof the holder.
 6. The brush-like grindstone according to claim 5,wherein a plurality of holders are disposed in the axial direction ofthe holders; and the plurality of linear grinding materials are held ineach of the plurality of holders.
 7. The brush-like grindstone accordingto claim 1, wherein two holders are disposed as a pair in an axialdirection of the holders; and the plurality of linear grinding materialsextend radially from a circumferential surface of the two holders, andcurve in a direction whereby the distal ends of the plurality of lineargrinding materials held in the two holders are close to one another. 8.The brush-like grindstone according to claim 1, wherein each of theplurality of linear grinding materials extends in an axial directionfrom an end surface of one side of the holder in the axial direction,and curves outwards from an inside of the end surface of the one side.9. The brush-like grindstone according to claim 1, wherein each of theplurality of linear grinding materials extends in an axial directionfrom an end surface of one side of the holder in the axial direction,and curves inwards from an outside of the end surface of the one side.10. The brush-like grindstone according to claim 1, wherein theplurality of linear grinding materials are held in the holder as aplurality of bundles.
 11. The brush-like grindstone according to claim1, wherein the plurality of linear grinding materials are held along theentirety of the circumferential direction in a circumferential grooveformed on an outer circumferential side surface or on an end surface ofone side of the holder.
 12. The brush-like grindstone according to claim1, wherein the plurality of linear grinding materials have an ellipticalor oval cross section in which a minor axis faces a direction ofcurvature.
 13. The brush-like grindstone according to claim 1, wherein adrive shaft extends from the holder in an axial direction. 14.(canceled)